Police are searching a house in Kent for a second body, after it emerged that the remains discovered there on Monday are not those of the missing 18-year-old Dinah McNicol but of another teenager who disappeared 16 years ago.

Detectives confirmed yesterday that the body uncovered at the house in Irvine Drive, Margate, is that of Vicky Hamilton, 15, who was last seen in February 1991 close to her home in Bathgate, West Lothian. The remains were found buried in a pit in the back garden.

A 60-year-old man, Peter Tobin, was charged in July with Hamilton's murder. Tobin was living at the address in Irvine Drive for part of 1991. He will appear today in private at Linlithgow sheriff court.

The house had initially been searched by officers from Essex police investigating the disappearance of McNicol, who vanished six months later, after they received information directing them to the property.

Yesterday the officer leading that investigation said he still believed her body might be buried there.

"We had reasons to come here. Those reasons still exist," said Detective Superintendent Tim Wills. "We came here for Dinah. And we haven't yet finished.

"There is a chance that she is here. In fairness to the family we need to fully answer the question as to whether she was here at any time."

Forensics officers were continuing to search the garden and to lift the floorboards inside the house yesterday. "I will not leave the house until I am satisfied that there is not any other human remains at this site," Wills said.

"Once we have completed work at ground level, a deep search and forensic examination of the fabric of the house will begin. This is a process that could take a number of days."

Asked about whether other bodies might be buried there he said: "I am here to search for Dinah and I have no reason at this stage to think there might be other bodies at the site."

Hamilton's disappearance led to Scotland's biggest missing person investigation, in which 7,000 people were interviewed and 4,000 witness statements taken. The case was reopened in November as a murder investigation.

Her father, Michael Hamilton, was informed of the discovery yesterday, but was unavailable for comment. Speaking in July, he said: "I have felt for a long time that [Vicky] was lying in some grave where she should not be.

"There was a time I thought Vicky had been forgotten. But I know the police were working hard to solve Vicky's case."

Dinah McNicol's father, Ian, said he was upset that the body was not that of his daughter, but that he still believed she might be buried at the house.

"My family hoped it was Dinah so we could put her to rest and go through our grieving process but obviously we can't now. But it's not finished, they are looking to see if there's more bodies there.

"They are going to wrap up the house and garden and tear it half down because they think there might be other bodies there."

The jazz musician and father of six said he had been told by police that his daughter's cash card had been used in Margate after she disappeared, leading them to believe she may have been at the house.

McNicol disappeared while hitchhiking home from a music festival in August 1991, after accepting a lift from a man who has never been traced.

Her father offered his condolences to Hamilton's family, saying: "I really feel for the poor girl's family but at least now they can grieve.

"I know what it's been like for them, waiting for news. In some ways I wish it was my daughter because at least they will be able to grieve now and bury her, but I feel so sorry for them too.

"I want to be able to grieve for Dinah, to be able to bury her or cremate her properly and go through the normal grieving process. Her being missing is worse, 10 times worse.

"I'm 68 now and I haven't got long left, because of this. I desperately want to lay Dinah to rest before my time comes."